The present invention relates to a reference voltage generating circuit.
In order to enhance precision of semiconductor circuits, and particularly analog circuits, those having a smaller variation of reference voltage against temperature variation are required.
For such a requirement, a reference voltage generating circuit such as the one described below is disclosed in U.S. Pat. No. 7,420,359 (Patent Document 1), for example.
A voltage obtained by resistance-dividing a voltage which is retrieved from a resistor coupled to a BGR (BandGap Reference) circuit and which is proportional to the absolute temperature (PTAT voltage: Proportional To Absolute Temperature voltage) and an output voltage of the BGR circuit is input to a correction circuit including a differential pair. The differential pair of the correction circuit generates a correction current according to the difference of input voltage which varies according to the temperature. Causing the generated correction current to flow again in the resistance coupled to the BGR circuit corrects the reference voltage which is output from the BGR circuit and varies according to the temperature variation.